Help: HO Spectrum 4-8-2 pilot truck derailing!

Model Railroader General Discussion (Model Railroader)
1

Hey gang,

Need some more help with my spectrum locos…now my Beautiful (at least in looks) C&O J-2 4-8-2 steamer runs around the layout but eventually the pilot truck derails. This just started today–and I have run the loco previous evenings with no problems.

I thought my 22" curves were perhaps the issue, but why would it run for hours and hours before and then all of a sudden derail? Now it runs a couple times around the level layout and the 2-axle pilot jumps the track.

I am using EZ track nickel silver sectional.

I already bought a Spectrum Decapod that kept shorting out on me—which is now on its way back to Bachmann. Is this the norm for HO Bachmann spectrum in HO?

Regards,

TP Metzger

2

I haven’t had any problems with any of my Spectrum steam engines. I forget who mentioned these trouble shooting ideas on a previous posting so here goes: does it derail in the same spot everytime it occurs, have you checked the rail joints to see if they are level or even with each other, have you changed anything on your track or roadbed, have you modified the loco in any way recently? Maybe check the pilot truck spring to see if it has caught on something and has been deranged, how does it run without the pilot truck spring,check the front coupler height maybe it’s dragging and catching on a high spot such as a frog or a crossover, have you checked the pilot truck to make sure the wheels and axles are in their proper positions? Hope these ideas help and if they do someone else gets the credit.

3

Is the wheel set in gauge?

Jim

4

If it was working fine and then quit working fine, then something has changed. Check to see if there is an gunk/dirt build up on the wheels. If it is derailing in the same spot, check the trackwork, because it can change. Check to see if any screws or other fasteners on the loco have gotten loose. See if the coupler has drooped down too low. Make sure there is no lint/pet hair build up anywhere on the engine (I have seen hair get wrapped around an axle and it was a bear to find).

5

If it happens in the same place, it is almost certainly the track that has changed. The loco may be sufficiently heavy that it has actaully caused the track to settle or shift. However, the longer wheelbase may have caused a slight separation at a joint, and the flange outboard on the curve is picking the far rail end.

Place a 12" or longer straightedge on that spot and look under it, along the rail tops. Is there an obvious depression? Bingo. Try shimming up that join, but on the outer side. If that doesn’t work, try the inner side, too.

Every time I have encountered this derailment problem with a new loco, it has been the track.

6

Hey thanks everyone for the tips!!! But it looks like the problem was my benchwork–a noticable (although slight) lip made the EZ track unlevel. Funny though that it didn’t eat it on the curves the first 4 or so hours of running <???>

I did two things that seemed to narrow down the possible problems. First, I took the pilot truck OFF the loco, and ran the loco around the layout. If the pilot truck was the problem, the loco would be fine without it, right? This actually was interesting not just in looks, but coming out of the curve the front driver jumped the rail. I put the pilot truck back on, ran it on the curve and sure enough–not just the pilot truck but the front driver jumped the track again. This told me that perhaps indeed it was my roadbed./benchwork. It looks like, after leveling the section, and running the loco problem-free for about an hour, that my steamer’s derailing has nothing to do with the engine itself (whew!).

I have found that my steamers are very fussy with trackwork vs. diesels. My diesels have no problems going over such unlevel aberrations. The steamer

7

Those were all good suggestions and it is good to hear that you solved your problem. It is not at all unusual for a steamer to run good at first and then, after a few runs around the layout, start to derail. Probably because tight parts loosen up a bit and things get a little more broken in, so to speak.

One other solution to a lot of problems with steamers is to add weight to the pilot truck. As the lead and first part of the engine on the rails, it will find every flaw in the track. A little extra weight will hold the pilot down on the track and forgive a lot of track flaws. Usually, if the pilot truck doesn’t derail, the driver wheels will stay on the rails as well.

The other problem with steamers is the trailing truck under the cab. Most of the derailing problems there are manufacturer-related in the design. Too light, too springy, etc. Again, a little extra weight on the trailing truck will usually solve the problem.

8

Between questions asked and things seen firsthand in the process of buying Spectrum locomotives, I have formed conclusions regarding working conditions in their factories.

Since some locomotives are bound up/out of quarter and some aren’t, since some Spectrums have random dabs of CA where no details live or ever thought of living, since some headlights work and others don’t, since some engine/tender wiring harness are painted black and others remain in original brightly colored plumage, since some major components are painted and rubbed to a fine finish and other parts are coated with alkali residue, it is my opinion that behind the facade of a modern fabrication and assembly plant, four monkeys in a tree, an old one and three very young ones, do most of the assembly work.

With that in mind, I pose the following question: What is the purpose of a spring that cannot act upon any of the other parts it is installed next to?

On four out of four Spectrum 4-6-0s, the spring which is ostensibly installed to help press the leading truck down against the rails has been perfectly flat. Not only does it not press against the boiler and transmit a downward force through compression, it doesn’t touch anything enough to even stay where it is supposed to, and is usually found not even engaging the lead truck, instead flopping aimlessly side to side.

There are only two possibilities. One, Bachman has atempted to design a new system of locomotive weighting, based on small thin leaves of brass, and two, that strip of brass was actually supposed to have some curvature to it, and a hook at the very tip to engage the concurrent depression in the front truck, rather than being flat, and long ago, the chimpanzees discarded the “bend brass strip” step in favor of eating bugs from each other’s coat.

Noting also that each new locomotive always has its idiosyncracies, which can help you really fine tune your track system, and that the more sprung weight carrying the locomoti

9

Hey does this 4-8-2 I have have a spring in the front pilot somewhere? I don’t see it anywhere.

10

Mine does, a small metal leaf directly above the pivot bar for the front axle. Removing the screw at the pivot point of the pivot bar should allow you to access the spring, but I haven’t had mine apart that way, only the 4-6-0’s. My 4-8-0’s spring has a healthy curve to it from the factory, unlike all of the 4-6-0’s, which were dead flat. You can see the spring without disassembly, from the side under good light.

Check your exploded parts view to see if removing that screw impacts any other assemblies before you pull it. On the 4-6-0’s, it does not. Also on the 4-6-0’s there is slightly less than necessary clearance between the pivot point and the gear cover in removing both the pivot arm and the spring, so far, gentle wiggling gets both of them out and back in without any damage. A magnetic appropriately sized Phillips screwdriver makes getting the pivot screw back in place easier, but a fingernail under the screw head holding it on the driver points works too, just takes a few more tries, on average, to get it started.

If my earlier post seemed like a cruel slam on Bachman, it wasn’t intended that way. I love my Spectrums, they fill a market niche that can’t be filled any other way. But they do have quality control problems, and these are bad enough to surprise anyone not expecting them in advance.

I test all my locos in the store for function and appearance, have worked things out with the store for special orders that have to be sent back, (the current policy of ordering three to get two decent ones seems to be working well) and except for having to wait longer between ordering and taking possession of properly functioning equipment, easily avoid the QC problems and still get beautiful looking locomotives that also run as intended.

The “four monkeys” bit was intended as hu